User's guide of Proceessing Modflow 5.0

202 Processing Modflow
- Search Method:
5.2 The Field Interpolator
Fig. 5.4 Linear, power and logarithmic model
The interpolation algorithms use three search methods to find a certain number of the
measurement data points to interpolate a cell value. The search methods are called SIMPLE,
QUADRANT and OCTANT. The search radius is assumed to be infinitely large.
The SIMPLE search method finds the data points nearest to the model cell. The
QUADRANT or OCTANT search methods find closest data points from each quadrant or
octant around a model cell (Fig. 5.5a and 5.5b). The number of data points used in a search
is defined by the Data Per Sector value. If fewer than Data Per Sector points are found in
a sector, the program uses the other nearest points found in the entire model. The valid range
of Data Per Sector is
SIMPLE 3#Data Per Sector#30
QUADRANT 1#Data Per Sector#7
OCTANT 1#Data Per Sector#3
The search method defaults to OCTANT search. Octant or quadrant searches are usually
used when the measurement points are grouped in clusters. These search methods force the
interpolation programs to use measurement data points radially distributed around the model
cell. They usually introduce more smoothing than a SIMPLE search.
Note that the entries in Search Method are ignored when Renka's triangulation algorithm
is used.
- GO:
To start the interpolation, simply click the button GO. The field generator creates and writes
the settings and the coordinates to a batch file PMDIS.BAT and two ASCII files
PMDIS_IN.{1} and PMDIS_IN.{2}. After having created these files, PMDIS.BAT will be
run in a DOS-window. The created ASCII files are used by the interpolation program.